Download Universal Serial Bus Controller Driver?

Where can I download  the Universal Serial Bus Controller driver for a dell inspiron 5100 windows XP? These "geek squad" guys from best buy told me to go to the device manager and delete everything under the USB section, and then when i restarted my computer, they would automatically reinstall, however, windows is detecting 2 Universal Serial Bus Controllers, but it can't find the software to install them. So i guess i need to download the drivers, but i can't find them anywhere. Any help is appreciated.